A Framework for Automatically Recovering Object Shape, Reflectance and Light Sources from Calibrated Images

Bruno Mercier (1) , Daniel Meneveaux (1) , Alain Fournier (2)

1 SIC - SIGNAL-IMAGE-COMMUNICATION
2 Imager Lab

In this paper, we present a complete framework for recovering an object shape, estimating its reflectance properties and light sources from a set of images. The whole process is performed automatically. We use the shape from silhouette approach proposed by R. Szeliski in [40] combined with image pixels for reconstructing a triangular mesh according to the marching cubes algorithm. A classification process identifies regions of the object having the same appearance. For each region, a single point or directional light source is detected. Therefore, we use specular lobes, lambertian regions of the surface or specular highlights seen on images. An identification method jointly (i) decides what light sources are actually significant and (ii) estimates diffuse and specular coefficients for a surface represented by the modi- fied Phong model [25]. In order to validate our algorithm ef- ficiency, we present a case study with various objects, light sources and surface properties. As shown in the results, our system proves accurate even for real objects images obtained with an inexpensive acquisition system.

Mots clés: shape from silhouette; marching cubes; multiple light sources detection; reflectance properties

Domaines: Vision par ordinateur et reconnaissance de formes [cs.CV]; Synthèse d'image et réalité virtuelle [cs.GR]

Bruno Mercier, Daniel Meneveaux, Alain Fournier. A Framework for Automatically Recovering Object Shape, Reflectance and Light Sources from Calibrated Images. International Journal of Computer Vision, 2007, 73 (1), pp.77-93. ⟨10.1007/s11263-006-9273-y⟩. ⟨hal-00331473⟩